1. Field of the Invention
The present invention relates to a bracket for fixing a rubber mount or elastic mount to one of two members which are elastically connected to each other through the elastic mount, an assembly of the elastic mount and the bracket, and a method of producing the bracket.
2. Discussion of the Related Art
In a vibration system such as a system adapted to elastically support a vibrating member like a power unit including an internal combustion engine and a muffler or exhaust pipe, there is known an elastic mount including a rubber member, which is interposed between two members which are elastically connected to each other through the elastic mount so as to damp a vibrational load applied therebetween. A metallic bracket is usually used for fixing such an elastic mount to one of those two members, taking account of the fixing efficiency and the construction of the member to which the elastic mount is fixed. In particular, brackets made of an aluminum alloy have been recently employed in place of conventional iron brackets, in an effort to reduce the weight and increasing the natural frequency (resonance frequency) of the bracket.
Generally, aluminum alloys have generally higher thermal conductivity than irons, and heat is more likely to be transferred through the aluminum alloy bracket from the member to which the elastic mount is fixed, to the elastic mount. Therefore, where the elastic mount is an engine mount fixed to an engine or a muffler mount fixed to a muffler, the elastic mount tends to be heated due to transfer of heat from the engine or muffler to the elastic mount, whereby the elastic mount tends to suffer from thermal deterioration and reduced durability.
While the elastic mount may be made of a highly heat-resistant rubber material, this solution to the above problem results in reduced freedom of choice of the rubber material, making it difficult to provide the elastic mount with desired dynamic vibration damping characteristics (e.g., a sufficiently high dynamic spring constant). Therefore, the above solution is not necessarily satisfactory.